Flutter谷歌机器学习翻译插件google_mlkit_translation的使用

Google’s ML Kit On-Device Translation for Flutter

这是一个Flutter插件，用于在设备上使用Google的ML Kit进行文本翻译。该插件支持超过50种语言之间的动态翻译。

重要说明

1. 平台支持：Google的ML Kit仅支持移动平台（iOS和Android应用）。Web或其他平台不受支持。
2. 维护者：此插件不是由Google赞助或维护的。作者是热衷于机器学习的开发者，他们希望将Google的原生API暴露给Flutter。
3. 平台通道：此插件使用Flutter平台通道来传递消息。所有机器学习处理都在原生平台上完成，而不是在Flutter/Dart中。

要求

iOS

• 最低iOS部署目标：15.5.0
• Xcode 15.3.0 或更新版本
• Swift 5
• ML Kit不支持32位架构（i386和armv7），只支持64位架构（x86_64和arm64）

在Xcode中排除armv7架构：

platform :ios, '15.5.0'

$iOSVersion = '15.5.0'

post_install do |installer|
  installer.pods_project.build_configurations.each do |config|
    config.build_settings["EXCLUDED_ARCHS[sdk=*]"] = "armv7"
    config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = $iOSVersion
  end

  installer.pods_project.targets.each do |target|
    flutter_additional_ios_build_settings(target)
    target.build_configurations.each do |config|
      if Gem::Version.new($iOSVersion) > Gem::Version.new(config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'])
        config.build_settings['IPHONEOS_DEPLOYMENT_TARGET'] = $iOSVersion
      end
    end
  end
end

Android

• minSdkVersion: 21
• targetSdkVersion: 33
• compileSdkVersion: 34

使用指南

On-Device Translation

创建OnDeviceTranslator实例

import 'package:google_mlkit_translation/google_mlkit_translation.dart';

final TranslateLanguage sourceLanguage = TranslateLanguage.chinese;
final TranslateLanguage targetLanguage = TranslateLanguage.english;

final onDeviceTranslator = OnDeviceTranslator(
  sourceLanguage: sourceLanguage,
  targetLanguage: targetLanguage,
);

处理文本

String textToTranslate = "你好，世界！";
String translatedText = await onDeviceTranslator.translateText(textToTranslate);
print(translatedText); // 输出: Hello, world!

释放资源

await onDeviceTranslator.close();

管理远程模型

创建ModelManager实例

final modelManager = OnDeviceTranslatorModelManager();

检查模型是否已下载

bool isDownloaded = await modelManager.isModelDownloaded(TranslateLanguage.english.bcpCode);
print(isDownloaded); // 输出: true/false

下载模型

bool downloadSuccess = await modelManager.downloadModel(TranslateLanguage.english.bcpCode);
print(downloadSuccess); // 输出: true/false

删除模型

bool deleteSuccess = await modelManager.deleteModel(TranslateLanguage.english.bcpCode);
print(deleteSuccess); // 输出: true/false

示例应用

你可以在这里找到完整的示例应用：Example App

完整示例代码

以下是一个完整的示例代码，展示了如何使用google_mlkit_translation插件进行文本翻译：

import 'package:flutter/material.dart';
import 'package:google_mlkit_translation/google_mlkit_translation.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: TranslationScreen(),
    );
  }
}

class TranslationScreen extends StatefulWidget {
  @override
  _TranslationScreenState createState() => _TranslationScreenState();
}

class _TranslationScreenState extends State<TranslationScreen> {
  final TextEditingController _textEditingController = TextEditingController();
  String _translatedText = '';

  final TranslateLanguage sourceLanguage = TranslateLanguage.chinese;
  final TranslateLanguage targetLanguage = TranslateLanguage.english;

  late OnDeviceTranslator _onDeviceTranslator;

  @override
  void initState() {
    super.initState();
    _initializeTranslator();
  }

  Future<void> _initializeTranslator() async {
    _onDeviceTranslator = OnDeviceTranslator(
      sourceLanguage: sourceLanguage,
      targetLanguage: targetLanguage,
    );

    // 检查并下载模型
    final modelManager = OnDeviceTranslatorModelManager();
    bool isDownloaded = await modelManager.isModelDownloaded(sourceLanguage.bcpCode);
    if (!isDownloaded) {
      await modelManager.downloadModel(sourceLanguage.bcpCode);
    }
    isDownloaded = await modelManager.isModelDownloaded(targetLanguage.bcpCode);
    if (!isDownloaded) {
      await modelManager.downloadModel(targetLanguage.bcpCode);
    }
  }

  Future<void> _translateText() async {
    String textToTranslate = _textEditingController.text.trim();
    if (textToTranslate.isNotEmpty) {
      try {
        String translatedText = await _onDeviceTranslator.translateText(textToTranslate);
        setState(() {
          _translatedText = translatedText;
        });
      } catch (e) {
        print('Error translating text: $e');
      }
    }
  }

  @override
  void dispose() {
    _onDeviceTranslator.close();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Google ML Kit Translation Example'),
      ),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          children: [
            TextField(
              controller: _textEditingController,
              decoration: InputDecoration(labelText: 'Enter text to translate'),
            ),
            SizedBox(height: 20),
            ElevatedButton(
              onPressed: _translateText,
              child: Text('Translate'),
            ),
            SizedBox(height: 20),
            Text(
              'Translated Text:',
              style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
            ),
            SizedBox(height: 10),
            Text(
              _translatedText,
              style: TextStyle(fontSize: 16),
            ),
          ],
        ),
      ),
    );
  }
}

这个示例展示了如何创建一个简单的Flutter应用程序，用户可以在其中输入文本并点击按钮进行翻译。翻译结果会显示在界面上。希望这个示例能帮助你更好地理解和使用google_mlkit_translation插件。